1. Field of the Invention
The present invention relates to a pixel information readout method for reading pixel information from an image pickup device, such as a CMOS (Complementary Metal-Oxide Semiconductor) image sensor, and an image pickup apparatus therefor.
2. Description of the Related Art
CMOS image sensors, mounted on digital still cameras, digital video cameras, mobile-phone cameras, web-cameras for video chat, and the like, are coming into ever-wider use today. And digital still cameras and the like often feature a variety of adaptive controls, which include exposure time control, white balance control, and movement detection for camera shake compensation. For these adaptive controls to function properly, it is necessary that information on brightness and color be obtained from an entire screen as image processing parameters.
Thus, to grasp a general tendency of a whole image, pixel information in a lower part thereof cannot be ignored when pixel information on the whole image picked up by a CMOS image sensor or the like is read out. And it takes time to read an image successively from top to bottom to acquire image processing parameters. Moreover, the timing for starting each of such adaptive controls comes only after image processing parameters have been acquired from the entire read-out image and compensation values have been generated by referring thereto.